原位合成TiC颗粒增强铁基复合材料的组织和性能
Structure and Properties of TiC Particulates Reinforced Fe Matrix Composite Produced In-situ
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摘要: 以钛粉、铁粉和炭黑为原料,原位反应合成了TiC/铁基复合材料;用扫描电镜、X射线衍射仪对其进行了组织分析,用热分析法对铁-钛-碳体系原位合成的反应机理进行研究,用MM-200型磨损试验机研究了该复合材料的耐磨性能.结果表明:复合材料相组成为TiC 和α-Fe,生成的硬质相TiC颗粒细小,在铁基体中均匀分布;铁-钛-碳的反应机理为,首先在765.6 ℃发生铁的同素异构转变,即α-Fe→γ-Fe,其次在1 078.4 ℃钛与铁共熔而形成低共熔体Fe2Ti,最后碳与Fe2Ti在1 138.2 ℃反应生成TiC;在重载干滑动条件下,该复合材料显示了良好的耐磨性能.Abstract: TiC/Fe matrix composite was in situ synthesized by sintering compacts of mixed iron,titanium and carbon black powders.The microstructure of composite was investigated using X-ray diffraction and scanning electron microscopy.With the help of differential thermal analysis,the reaction mechanism of the Fe-Ti-C system was discussed.The wear-resistance of TiC/Fe matrix composite was examined using an MM-200 wear test machine.The results show that the synthesized composite consistes of TiC and α-Fe.TiC particles exhibite fine size and homogeneous distribution in the matrix.The reaction mechanism is as follows.First,allotropic change of α-Fe→γ-Fe occurred at 765.6 ℃.Second,the compound Fe2Ti was formed at 1 078.4 ℃ because of the eutectic reaction between Ti and Fe.Third,reaction between carbon and melted Fe2Ti caused the formation of TiC at 1 138.2 ℃.Under the condition of dry sliding with heavy load,TiC/Fe matrix composite showed great wear-resistan